This invention relates generally to liquid-propellant rocket engines and, more particularly, to liquid-propellant engines that develop relatively low thrusts, in a range less than 5 pounds (2.3 kg). Such engines are typically used in satellites for attitude control, and course correction or station keeping.
Liquid-propellant rocket engines may be of the bipropellant type, in which separate streams of fuel and oxidizer are injected into the engine, or of the monopropellant type, in which a single fuel stream is injected into the engine onto a catalyst bed. In the bipropellant engine, the fuel and oxidizer are injected from narrow-bore propellant lines as relatively narrow streams of liquid. The fuel and oxidizer lines are oriented in such a manner that the streams intersect in the combustion chamber of the engine.
In both types of engines, the liquid propellants are stored under pressure and fed to the engine through propellant lines. High-pressure propellant tanks add significantly to the weight of the vehicle in which they are installed. There is, therefore, a need for a liquid-propellant delivery system that avoids the use of high-pressure fuel tanks and oxidizer tanks. The present invention is directed to this end.